1. Field of the Invention
The present invention relates to a cellular phone and a mail security processing method for the same, and in particular, to a cellular phone and a mail security processing method for the same of guaranteeing security of transmission mail and received mail.
2. Description of the Prior Art
Cellular phones have been widely developed and spread these days and hence have been used to communicate pieces of mail. The mail includes business mail and private mail. It is desired that some pieces of mail are not read or accessed by a third party.
Japanese Patent Application laid open No. 2002-149570 and No. 2002-373140 describe conventional techniques to prevent a third party from reading a predetermined piece of mail.
According to Japanese Patent Application laid open No. 2002-149570 entitled “Cellular Phone and Mail Display Control Method”, mail is classified into mail with lock (not to be read by a third party) and mail without lock according to specifications from the user. Utilizing a secret number, a piece of mail is stored. The piece of mail thus locked is unlocked or released using the secret number. The pieces of mail with lock and those without lock are both displayed.
According to Japanese Patent Application laid open No. 2002-373140 entitled “Cellular Phone”, mail desired not to be read by a third party is set as secret mail. The secret mail is not displayed in a list, and any piece of mail obtained from a specified mail address can be set as secret mail.
However, according to Japanese Patent Application laid open No. 2002-149570, the mail with lock and that without lock are both displayed. If a third party intentionally views the mail stored in the cellular phone, the third party possibly becomes offended because the mail with lock exists therein. In operation, the user specifies each piece of mail for mail with lock or for mail without lock.
According to Japanese Patent Application laid open No. 2002-373140, some pieces of mail associated with a predetermined mail address can be set as secret mail at a time. However, ordinarily, each piece of mail is specified for secret mail to be saved in the system.